Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1887-11-18
Clouds and Rain.

explained the theory OF storms the other
day.
"Storms are caused" he said, First,
by the meeting and commingling of in
equal atmospheric temperatures or
pressureS; second, by the rotation of
the earth, and third, by unequal specific
gravity of different layers of air. The
first of these causes is the prime one;
the other two are but of secondary and
comparatively slight Importance in the
generation OF a storm.
at is well-knOwn fact that warm
air rises. 1t is equally well-known that
the earth becomes heated by the suns
rays falling upon it, and BY the absorp-
ton and radiation of this stored up heat
renders the temperature higher at the
surface than at elevated points. For a
time this hot air Oh the surface is kept
down by atmospheric pressure, but
there comes time when the expansion
becomes 30 great as TO break through
the cold air pressure and the hot air
goes up with rush, rising sometimes
10 great height. As the warm air rises,
it creates vacuum below, and the
cooler air rushes in from all sides TO ill
It's place. This cool air as it gets gradu-
ally heated, also rises, and more cool air
rushes in to again ill the vacuum.
Right at this point where the hot air
first rises is the center of storm. The
vacuum caused by the ascending hot air
sucks into its vortex the air from every
point of the compass, ard this suction
causes wind, but places affected by
storm thus formed, it will be seen, will
have the wind from different points of
the compass, according 10 their direction
from the storm center. Thus, locality
directly south Of storm center will
have the wind from the south, as it
rushes north. When this warm air has
accumulated at a sufficiently high alti-
tude, and becomes surrounded by cooler
air the moisture in 1t begins TO condense,
forming rain.
1.-The rushing in of the cold air TO I'LL
the vacuum caused by the rising hot air
gives motion TO the accumulation OF
warm air, and it begins TO whirl about
in circle, but at the centre all is calm
and clear. Thus it is that sometimes we
experience u lull in the storm, as II is
called. Such brief respite is nothing
more than the passing of storm centre
directly overhead, though the sun even
may shine unobstructeily.
"As this storm keps whirling about
overhead it continues to gather energy,
and grows by the accession Of more
heated air, exactly as SNOWFALL is in
creased in diameter by rolling II in the
snow At last the accumulation becomes
- ------.' - 49,, ~Hants
of the earth's rotation, and IL begins 10
move. This rotation Of the earth, being
from West to East, gives all the storms
of any extent the same general direction.
Such general direction, however, from
West to East, is liable to DETECTION
from various causes, such as mountains,
of the atmosphere, by coming
in contact with other storms or air cur
rents, and by large areas OF water.
"Nine out Of ten American storms
originate in the mountainous regions OF
the Northwest, where the warm air %
the valleys rises and comes In contact |
with the cool air from the great eleva-
tions of the Rocky mountains. These .
storms take a generally southeasterly !
direction until they get into the dry
regions OF Kansas, and there becoming
famished, "a 1t were for want Of moist
urc. and as If seeming the water for
which they long from the direction Of
the great lake region, they make turn
to the Northeast and proceed TO the
Great Lakes, where they ABSORB abund- 7
ence Of moisture, and then travel on
east, deluging us with this water from
the Lakes. All such general storms
pass out from this country to the Allan
tic, through the st. Lawrence valley.
Within recent years these American
storms have been actually traced across
the Atlantic to Europe, and some Of them
even as far as Asia.
"All stormz originate In the same
way whether on land or at sea; In sum.
mer or In winter. The under current
of air which rises need not necessarily
be warm to make II rise; as, for In
stance, where the temperature Is below
the freezing point; but the under cur
rent must be Of higher temperature
than that above and surrounding IL to
force il TO rise. In other words, a storm
is originated by commiugling Of une-
quail atmospheric temperatures.
Cyclones arise at sea, and though
generated just ia land storms are, re-
volye with much greater rapidity and
cover much smaller areas. They travel
in a serpentine course, and ia no one
general direction, with the greatest
force Of wind at the centre Of the storm.
"a tornado Is a tower or spiral storm,
which travels in band across the cOun-
try. 1t differs from a cyclone prinei-
pally in that one Of its characteristics is
to suck, or draw up anything movable
over which it passes, and this confines
its destructive operations TO very linn
ited area, while cyclone scatters de-
struction broadcast. A hurricane IL the
same thing as tornado.
"The difference between high aud
a low barometer storm is that with
high barometer the wind is thrown OF
from the circumference of the Storm
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